In diverse fields of engineering, there exists a requirement to engage two tubular members in permanent or semi-permanent relation. Welding, glueing, swaging and brazing are all known techniques for attaching tubes. However, each of these techniques is subject to a failure threshold; as the strain on the joint increases, the probability of failure increases, and having failed, the joint requires a repetition of the joining process to reform. Such failure may be detrimental or dangerous in the context of the application of the joint, and repair may be difficult.
One field in which the failure of welded, swaged or glued joints is particularly disadvantageous is in the construction of medical devices, particularly catheters. Catheters are tubular structures which are navigated through body cavities to perform some diagnostic or therapeutic function at a specific location within the body. If a joint in a catheter fails, there is risk not only of failure of the process for which the catheter is used but also of further risks due to the presence of a structurally compromised and thus unpredictable foreign body inside a patient's body. The presence of such risks restricts the use of catheterization techniques to cases where the risks can be justified.
Accordingly, there is a need for a method of forming a joint between at least two tubular catheter elements which is able to resist such sudden failure modes.